/*
 * Copyright (C) 2008 feilong
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.feilong.excel.reader;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;

import com.feilong.excel.definition.LoopBreakCondition;

class BlockReaderLoopBreaker{

    /** Don't let anyone instantiate this class. */
    private BlockReaderLoopBreaker(){
        //AssertionError不是必须的. 但它可以避免不小心在类的内部调用构造器. 保证该类在任何情况下都不会被实例化.
        //see 《Effective Java》 2nd
        throw new AssertionError("No " + getClass().getName() + " instances for you!");
    }

    //---------------------------------------------------------------

    /**
     * Check break.
     *
     * @param sheet
     *            the sheet
     * @param rowIndex
     *            the row
     * @param columnIndex
     *            the col
     * @param loopBreakCondition
     *            the condition
     * @return true, if successful
     */
    static boolean checkBreak(Sheet sheet,int rowIndex,int columnIndex,LoopBreakCondition loopBreakCondition){
        //no break condition defined        
        if (sheet.getLastRowNum() < rowIndex){
            return true;
        }

        //---------------------------------------------------------------
        if (loopBreakCondition != null){
            Row row = sheet.getRow(rowIndex + loopBreakCondition.getRowOffset());
            if (row == null){
                return false;
            }

            //---------------------------------------------------------------
            Cell cell = row.getCell(columnIndex + loopBreakCondition.getColOffset());
            if (cell == null || cell.getCellType() != CellType.STRING){
                return false;
            }
            if (loopBreakCondition.getFlagString().equals(cell.getRichStringCellValue().getString())){
                return true;
            }
        }
        return false;
    }
}
